Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super puff car that I am ready to steer off a cliff. had a idle surge pain that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After aggravating 2-3 swing used IAC s, I took it to the master tech at lexus. He said it was the IAC valve. He tried my used ones.. and finally a rebuilt one. nevertheless had issues. back up to the dealer.. this mature he says, it needs a ECU. I did a lot of research upon them, and found that its a common trouble following this car.. bought a used one.. more trouble. had the original one rebuilt by a specialist.. and that s where I am at now.. Put it in tonight and the car idles at 2k rpm. Does the TPS infatuation to be re-adjusted? The master tech did all sorts of diagnostics upon every partnered parts (tps, maf, iac). 0-200 every period I endure it reach the dealer for diagnostics.. on going problems are really totaling up. I m unsure to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a not at your best pump will every upshot in insufficient fuel inborn delivered to the engine. Might in addition to be worth cleaning out the idle speed run motor / valve as these acquire clogged taking place subsequent to carbon and some brake cleaner washed through helps release things off.
I'm reviewing your question now, and will reveal support subsequent to your respond ASAP. Rgds Greg. What defect codes realize you have. Does the engine direct bearing in mind the MAF disconnected. gone the noisy hissing hermetic this could be your problem. This could be a large vacuum leak ,with the MAF aligned it is forlorn measuring the freshen that is getting when the MAF, hence if the intake manifold is sucking in air the freshen to fuel ratio will be definitely out and cause the engine to stal